Fixing compositions for photographic silver halide light-sensitive elements

ABSTRACT

A FIXING COMPOSITION FOR PHOTOGRAPHIC SILVER HALIDE LIGHT-SENSITIVE ELEMENTS CONTAINING AMMONIUM THIOSULFATE WHICH CONTAINS AT LEAST ONE COMPOUND REPRESENTED BY THE GENERAL FORMULA   R1-NH-C(=S)-N(-R2)-R3   IS DISCLOSED. THROUGH THE USE OF SAID COMPOSITION, A MARKED REDUCTION IN FIXING TIME IS MADE POSSIBLE.

United States Patent Olfice 3,565,621 Patented Feb. 23, 1971 3,565,621 FIXING COMPOSITIONS FOR PHOTOGRAPHIC SILVER HALIDE LIGHT-SENSITIVE ELEMENTS Shunichiro Tsuchida, Haruo Shibaoka, and Reiichi Ohi,

all of 210 Nakanuma, Minami-Ashigara Machi, Ashigara-Kamigun, Kanagawa, Japan No Drawing. Filed Mar. 29, 1968, Ser. No. 717,438 Claims priority, application Japan, Mar. 30, 1967, 42/20,250 Int. Cl. G03c 5/38 U.S. CI. 96-61 4 Claims ABSTRACT OF THE DISCLOSURE A fixing composition for photographic silver halide light-sensitive elements containing ammonium thiosulfate which contains at least one compound represented by the general formula NH-R S=C\ /R2 is disclosed. Through the use of said composition, a marked reduction in fixing time is made possible.

Field of the invention The present invention relates to a fixing composition for a photographic silver halide light-sensitive element, and more particularly to an improved quick fixing composition for a photographic silver halide light-sensitive element.

Description of the prior art In the usual photographic processing of a photographic silver halide light-sensitive element, after image exposure and development, the silver halide in the photographic light-sensitive element remaining unexposed is converted into a stable or inactive silver salt or into a water-soluble silver salt which is dissolved out of the photographic lightsenstive element.

A fixing composition is used for the latter processing, and for this purpose, various thiosulfates, such as sodium thiosulfate are employed.

To shorten the photographic processing period, ammonium thiosulfate, which dissolves the silver halide more quickly than sodium thiosulfate has frequently been used. An ammonium thiosulfate type fixing composition is effectively employed for processing a photographic light-sensitive element having a thick silver halide emulsion layer, such as, a photographic X-ray film.

However, the fixing speed of an ammonium thiosulfate-type fixing composition is markedly influenced by the type of developing composition used. Usually, a large amount of an alkaline material, such as potassium carbonate or potassium hydroxide, is used in a developer as a developing accelerator, but when employing such a potassium salt, the fixing speed of an ammonium thiosulfate-type fixing composition is reduced to a greater extent than when employing a sodium salt as the alkaline material. Besides such alkaline materials potassium bromide is widely employed as an anti-foggant, however, the fixing speed is also reduced by the presence of potassium bromide. 1

Recently, liquid photographic processing chemicals have been utilized. A liquid processing composition having a high concentration is desirable. In particular, when processing a large number of photographic light-sensitive films using an automatic developing machine, for example, when developing photographic X-ray films, the amount of chemicals used in development is increased and, a highly concentrated liquid developer tends to be widely employed as more convenient.

When a highly concentrated liquid developer is used, a compound having high solubility is desirable and, in such a case, the concentration of the liquid developer generally depends on the solubility of the alkaline material which comprises a large porportion of the developer. Since the solubility of potassium salts (such as potassium carbonate and potassium hydroxide) is higher than that of sodium salts, such potassium salts are frequently employed in a liquid developer. However, when processing photographic light-senstive films which have been developed in a liquid developer containing the above-mentioned potassium salts in an ammonium thiosulfate type fixing composition, there is a marked reduction in fixing speed. This Will cause problems when conducting the development using an automatic developing machine.

Therefore, an object of this invention is to provide a fixing composition containing ammonium thiosulfate capable of fixing at high speeds a photographic silver halide light-sensitive element which has been developed in a liquid developer. Best results are obtained when the developer has contained a potassium salt.

SUMMARY OF THE INVENTION Applicants have found that when at least one compound represented by the general formula N-Rs is added to a fixing composition for photographic silver halide light-sensitive elements which contains ammonium thiosulfate, that the fixing time may be markedly reduced. This reduction is most pronounced when the developing composition utilized prior to the fixing process contains a potassium salt.

Generally, R and R represent a member selected from the group consisting of a hydrogen atom, an amino group, an alkyl group, a hydroxyalkyl group, an aryl group, and an allyl group. R generally represents a member selected from the group consisting of a hydrogen atom, an alkyl group, a hydroxyalkyl group and an allyl group.

R and R may combine to form a heterocyclic ring, in which case it is necessary that R not be an allyl group.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Thus, according to the present invention there is provided an ammonium thiosulfate-type fixing composition for photographic silver halide light-senstive elements containing a compound represented by the general formula wherein R and R each represents a hydrogen atom, an amino group, an alkyl group, a hydroxyalkyl group, an aryl group or an allyl group; said R and R may combine to form a heterocyclic ring; and R represents a hydro gen atom, an alkyl group, a hydroxyalkyl group or an allyl group when R and R do not form a heterocyclic ring, but represents a hydrogen atom, an alkyl group or a hydroxyalkyl group when R and R form a heterocyclic ring, i.e., in this case R may not be an allyl group.

Examples of the compound represented by the above general formula are as follows, although the compounds 3 of this invention are not to be limited to only these compounds:

Compound 1 Compound 2 N HNHz Compound 3 NH O H2 C H: C H2 Compound 4 NH=CII Compound 5 NHCH2 NCI-Iz CHz-CH2OH Compound 6 NHCH3 CH3 An effective amount of the compound to be added to the fixing compound is from about 0.01 mol/liter to the maximum dissolvable amount thereof, but is preferably from 0.05 to 0.3 moi/liter.

The following examples show the advantages of an ammonium thiosulfate-type fixing composition containing each of the aforesaid compositions of this invention, but it should be understood that the invention is not to be limited thereby.

EXAMPLE I The measurement of the fixing speed was conducted under conditions identical to those of conventional photographic processing.

A highly-sensitive silver iodoa'bromide film was image Water to make 1 liter.

The photographic film thus developed was processed in a fixing solution having the following composition:

Ammonium thiosu1fate150 g. Sodium sulfite (H O) g. Sodium metaborate15 g. Glacial acetic acidl5 ml. Potassium alumg.

Water to make 1 liter.

4 In addition, a second sample of the photographic film processed in each of the aforesaid developers was processed in a fixing solution having the above composition but with the addition of 0.1 moi/liter of Compound 1 shown above. The fixing period was measured in each case. The results are shown in the following table.

TABLE I Fixing time, seconds Developing Developing 1O Additive Composition I Composition 11 None 66 32 Compound 1 45 32 1 The processing temperature in this experiment was 20 C. in the fixing processing, the developed film was quietly placed in the fixing composition. From the results it will be seen that the reduction in fixing speed caused by using a developer containing potassium bromide was largely prevented.

EXAMPLE II The same procedures as in Example I were repeated while using 0.1 mol/ liter of Compound 2 mentioned above w instead of Compound 1. The results of the experiment are shown in the following table. The processing conditions for the films were the same as in Example 1.

TABLE II Fixing time, seconds Developing Developing Additive Composition I Composition II None 66 32 Compound 2 42 32 EXAMPLE III The same procedure as in Example I was repeated while using 0.1 mol/ liter of Compound 3 instead of Compound 1. The results of this experiment are as follows:

TABLE III Fixing time, seconds Developing Developing Additive Composition I Composition II None 66 32 Compound 3 50 32 EXAMPLE IV Photographic X-ray films were processed as in Example C, while using 0.2 moi/liter of Compound 4 instead of Compound 1, and the merits of the addition of the additive of this invention were confirmed. The experiment Was conducted at 20 C. In the fixing processing, the film was quietly placed in the fixing composition. The results are shown in the following table.

TAB LE IV Fixing time, seconds Developing Developing Composition I Composition II Additive None Compound 4 1 0.2 mol/liter.

EXAMPLE V The same procedure as in Example IV was repeated while using 0.1 mol/ liter of Compound 5 instead of Compound 4. The results of this experiment are shown in the following table.

TABLE V Fixing time, seconds Developing Developing Additive Composition I Composition II None 8G 46 Compound 5 72 45 EXAMPLE VI The same procedure as in Example IV was repeated while using 0.1 mol/liter of Compound 6 instead of Compound 4. The results of this experiment are shown in the following table.

TABLE VI Fixing time, seconds Developing Developing Additive Composition I Composition II None 86 46 Compound 6 75 43 the following formula NHR1 wherein R and k each are selected from the group consisting of a hydrogen atom, an amino group, an alkyl group, a hydroxyalkyl group, an aryl group, and an allyl group, wherein said R and R together may form a heterocyclic ring, and wherein R is selected from the group consisting of a hydrogen atom, an alkyl group, a hydroxyalkyl group and an allyl group when R and R together are not a heterocyclic ring, and wherein R is selected from the group consisting of a hydrogen atom,

an alkyl group and a hydroxyalkyl group when R and R together form a heterocyclic ring.

2. The method as claimed in claim 1 wherein the amount of said compound ranges from 0.05 to 0.3 mol per one liter of the fixing composition.

3. The method as claimed in claim 1 wherein said compound is selected from the group consisting of 4. The method as claimed in claim 3 wherein the amount of said compound ranges from 0.05 to 0.3 mol per one liter of the fixing composition.

References Cited UNITED STATES PATENTS 2,930,692 3/1960 Gerhardt 9661 3,239,340 3/1966 Nasu et al 96 6l 3,243,296 3/1966 Nasu et al 96-61 OTHER REFERENCES Photographic Science & Engineering, vol. 4, No. 4 July-August 1960 pp. 186l95.

NORMAN G. TORCHIN, Primary Examiner M. E. KELLEY, Assistant Examiner 

